Especially for Newt Gingrich, who has used his run for President as a kind of savvy marketing campaign built around his political persona.

In the last five years the former Speaker of the House has lived a life of luxury built around his empire, including millions in private jet travel, paid for with donations to a political group he founded. Gingrich's lifestyle also includes a million-dollar home in suburban Washington and jewelry from Tiffany's.

"You can do very well by running for President," said Scott Reed, a Republican strategist. "You don't always have to win."

Sarah Palin, a little-known governor before John McCain picked her as his running mate in 2008, has turned her political celebrity into a multi-million dollar business, with books, paid speeches, and a reality TV show.

"There's a heck of a business out there for ex-politicians that have run," said Reed, who managed Sen. Bob Dole's 1996 presidential campaign. Reed said Palin actually has a "real choice" to make about running in 2012, "because she has a very lucrative career going right now."

But Reed says that for some Republicans this election cycle, running for President seems mostly about marketing -- about creating or enhancing a valuable brand name.

"I mean to me it's kind of a game," said Reed. "It makes their brand have some value."

And no one seems to have realized that more than Gingrich, who has not held elective office since 1999. When he was pressed on the half-million-dollar account that he and his wife Callista had with Tiffany's on "Face the Nation," Gingrich called it a "standard, no-interest account" and said he and his wife live on a budget.

"Go talk to Tiffany's," Gingrich told host Bob Schieffer. "All I'm telling you is, we are very frugal. We in fact live within our budget."

Earlier this month, Gingrich and Callista took a cruise in the Greek isles, which led virtually his whole staff to resign, questioning whether he was more interested in selling books and DVDs than running for president.

The Newt Gingrich Empire

Part of Gingrich's empire, a kind of Gingrich, Inc., includes several for-profit businesses. Gingrich Communications oversees his paid speaking engagements and Fox News contract. Gingrich Group provides consulting services. Gingrich Productions makes feel-good documentaries with themes grounded in religion and American tradition.

This week Gingrich also released his 24th book, with many of his upcoming campaign stops doubling as marketing events for his book and movies, raising more questions about the true intentions of the campaign.

"If he's being driven by book sales, and movie openings and things like that, that doesn't fit into a traditional campaign," said Reed.

Also raising questions from independent watchdog groups is the operation of a charity Gingrich founded, called Renewing American Leadership.

Its website contained ads for Gingrich's books -- taken down after ABC News asked about them -- and posted his positions on political hot-button issues.

"It's not clear that it is a charity," said Ellen Miller, executive director of the non-partisan good government group The Sunlight Foundation. "We have an organization that looks like he's mixing public purpose and his own private political purpose."

The charity's fundraising letters, on Gingrich's letterhead, attack President Obama and also promote Gingrich's book.

In fact, records show the charity bought Gingrich's books to give to those who send in donations.

There was no discount in the price, according to the charity's new director, Pastor Jim Garlow.

"My concern was, 'Is there any way we can get these a lot cheaper?' and we couldn't and we didn't," said Garlow.

A recent audit discovered that the charity paid one of Gingrich's for-profit companies more than $200,000, which the charity says was used to pay his then-press secretary Rick Tyler, who was also the director of the charity -- until March -- and made the decision to buy the Gingrich books with charity funds.

Garlow said he didn't think Gingrich's charity and political career had become too intertwined, and accused ABC News of misreading Gingrich's intent.

Said Garlow, "What's so intriguing about you, in the media, you can't believe people have pure motives. That's so hard for you. So difficult for you. You assume everyone's got evil motives."

Gingrich refused repeated requests to be interviewed about his empire, and had little to say when ABC News caught up with him Tuesday morning on his way to a speech.

"I'm not concerned about that," said Gingrich. "The American people are not concerned about that. Cover the speech."